Such ophthalmology systems include ophthalmology microscopes (also known as ophthalmic surgical microscopes) and optical coherence tomography (OCT) systems.
Ophthalmology microscopes are optical reflected light microscopes used during medical surgery in the ophthalmology and provide an image magnification of usually 5 to 30 times. In comparison to other optical reflected light microscopes, ophthalmology microscope have an increased focal length of the objective system in use of typically 175 mm to 550 mm. In this respect, ophthalmology microscopes are characterized in that they often do not directly image a fundus (fundus oculi/eyeground) of an eye but indirectly image the fundus of the eye. This is performed by imaging an intermediate image of the fundus of the eye wherein the intermediate image is generated by a lens of the eye together with an ophthalmology loupe (magnifying glass) disposed in front of the eye. The ophthalmology loupe is disposed at a distance of 4 mm to 80 mm from the lens of the eye. The ophthalmology loupe may be mounted to the ophthalmology microscope in a pivotable and/or releasable and/or exchangeable way. The field of view of ophthalmology microscopes, i.e. the area in the focal plane on the fundus which can be imaged onto the retina of a user by at least one imaging beam path at a particular point in time is typically greater than 1 mm2. Therefore, the field of view of an ophthalmology microscope does not only comprise one single image point, as in the case of scanning microscopes; instead, at each point in time, a multi-dimensional (two- or three-dimensional) imaging of the inspected object is performed by the ophthalmology microscope (into an image plane).
In order to provide a spatial impression of the object to be imaged to a user, which is especially necessary for surgeries of the eye, ophthalmology microscopes are often stereo microscopes simultaneously providing at least one pair of imaging beam paths to the eyes of the user, wherein optical axes of the imaging beam paths of the at least one pair intersect in proximity of a focal plane of the ophthalmology microscope at a stereo angle of 0.5° to 14°.
The image of the object imaged by the ophthalmology microscope is may be provided by an ocular (for stereoscopic ophthalmology microscopes by a pair of oculars) to a user. Additionally or alternatively, the image may be converted to electric signals by an image converter (for stereoscopic ophthalmology microscopes by a stereo image converter or a pair of image converters, respectively) and visualized for the user by a monitor and/or a head-mounted display. This visualization using a monitor or head-mounted display may be performed in addition to usage of oculars or as an alternative to usage of oculars.
In order to meet the requirements of ophthalmology, ophthalmology microscopes often have an integrated slit lamp and/or keratoscope.
OCT-systems are devices in which light of a short coherence length is used for measuring distances of scattering materials using an interferometer in order to determine structural information within a volume of an object and, in turn, obtain a sectional view of an object to be analyzed by scanning point by point. This method is referred to as optical coherence tomography (OCT).
Today, OCT is already used frequently for inspections of the eye. In particular, OCT may be used during a cataract-surgery during which the natural lens is removed from the capsular bag after the lens has been shattered and an intraocular lens is inserted. However, it has been found that only structures having a sufficiently high reflectance are suitable for being observed using OCT.
Occasionally, it is necessary to visualize liquids and gels in the eye of a patient in the field of ophthalmology. These liquids and gels are, for example, used during surgery (in particular a cataract-surgery) and may, for example, serve as substitute materials for natural liquids (e.g. for stabilizing the eye chamber after drainage of a aqueous liquid) in order to protect, for example, the endothelium of the cornea from injury, in order to separate, for example, different tissue from each other, or in order to serve, for example, as a tampon. Examples of such liquids and gels are so-called OVDs (ophthalmic viscosurgical devices), balanced salt solutions, silicone oils or perfluorocarbons. These liquids and gels used in ophthalmology are often colorless in order to avoid hindering an observation of the eye by the surgeon during the surgery. Furthermore, these liquids and gels should be partially or entirely removed after a surgery as they may, for example, increase the intraocular pressure (particularly relevant for OVDs), affect the sight of the patient (particularly relevant for silicone oils), or act toxic (particularly relevant for perfluorocarbons).
Among the OVDs are, for example, chondroitin sulfate, sodium hyaluronate and hydroxypropylmethylcellulose. OVDs have in common that they are viscoelastic and, therefore, have a partially elastic and partially viscous material behavior.
Due to their high transmittance the removing and in particular the fully removing of the liquids and gels used in ophthalmology for application in the eye of a patient is very difficult.
During a cataract-surgery, a dull eye lens is destroyed during a phacoemulsification using supersonic sound or a laser, and the residual debris are removed from the eye by a suction apparatus. Then, an artificial lens is inserted. A suction apparatus configured to emit supersonic sound is used as a part of a phacoemulsification device. A viscoelastic gel is often used as a rinsing liquid.
It is an object of the present disclosure to provide an ophthalmology microscopy-system and a method of operating an ophthalmology microscopy system, wherein both provide at least partially or fully removing liquids and gels used in ophthalmology for application in the eye of a patient in a particularly efficient way.
It is an alternative object of the present disclosure to provide a product applicable for application in an eye of a patient, wherein the product is a liquid or a gel having a high transmittance and, nevertheless, is visualizable in a reliable way.
It is emphasized that not all embodiments must solve both objectives simultaneously. In fact, it is sufficient if an embodiment solves one or even none of the aforementioned objectives.